網際網路上支援多媒體串流之封包排程與頻寬保留之研究

Scheduling and Bandwidth Reservation for Multimedia Streaming over the Internet

杜勇正(Yung-Cheng Tu)

指導教授 ： 石維寬

國立清華大學/電機資訊學院/資訊工程學系/博士(2007年)

摘要

對於網路提供者來說，在網際網路上對多媒體串流提供服務品質(Quality of
Service, QoS)的保證一直是個很重要的議題。為了支援這種服務品質保證，我們
在此提出了三種機制：(1)一個名為Jitter Control Frame-based Queueing (JCFQ)
的Frame-based 封包排程機制，(2) 為了支援預先保留頻寬的功能而設計的多階
段二階層頻寬保留機制，以及(3)一個名為 Bulk Scheduling Scheme (BSS) 的動
態頻寬保留機制。其中，JCFQ 可以像其他其它 Generalized Processor Sharing
(GPS)-based 的排程器一樣，提供良好的頻寬與封包延遲保證，但它卻只需要
O(1) 的運算複雜度。多階段二階層頻寬保留機制則是對於未知使用時間的多媒
體串流提供了一個較有效率且較有保障的頻寬保留方式。而BSS 是一個創新的
動態頻寬分配架構，它可以根據網路串流的流量以及延遲要求，在中途每個路
由上，動態的計算出合適的頻寬分配。跟傳統的per-packet 去計算要處理之封包
的方式比較起來，BSS 有較低的 computational overhad，且不需要去修改封包
的內容，這對於網路傳輸的保密也有很大的幫助。

關鍵字

多媒體串流 ； 服務品質 ； 封包排程 ； 頻寬保留

並列摘要

Providing QoS guarantees for multimedia streaming applications over the
Internet is an important issue for network providers. To support these guarantees, we
proposed three mechanisms, which contain a frame-based packet scheduling named
as Jitter Control Frame-based Queueing (JCFQ), a multi-stage two-leg bandwidth
reservation and admission control for advance reservations with uncertain service
durations, and a dynamic bandwidth allocation called Bulk Scheduling Scheme
(BSS). The JCFQ provides not only per-flow bandwidth and delay bound guarantees
as other Generalized Processor Sharing (GPS) based schedulers but also achieves
worst-case fair weighted fairness as Worst-case Fair Weighted Fair Queueing (WF2Q)
with O(1) computational complexity in selecting a packet to serve assuming the
number of flows is fixed. The multi-stage two-leg bandwidth reservation and
admission control provides users a more predictive, affirmative service guarantees
than conventional reservation schemes. The BSS is a novel framework that can
guarantee the end-to-end delay bound for the flows with variable-bit-rate traffic by
inserting some packets into flow traffic. Compared to traditional per-packet marking
approaches, the BSS has lower computational overhead in intermediate nodes and
does not change any information in the data packets, which allows end-to-end secure
transmissions possible.

並列關鍵字

Multimedia Streaming ； Quality of Service ； Packet Scheduling ； Bandwidth Reservation

參考文獻

[2] J. Bennett, and H. Zhang, “WF2Q: Worst-case fair weighted fair queueing,” in

Proceedings of INFOCOM’96, pp. 120-128, Mar. 1996.

[4] R. Braden et al, “Resource ReSerVation Protocol (RSVP) – Version 1:

Mechanisms in Distributed Multimedia Applications,” in Computer Networks

[6] L.-O. Burchard, “On the Performance of Computer Networks with Advance